All-solid bend-resistant large mode area fiber design with highly doped rods in the cladding

An all-solid bend-resistant large mode area fiber with six uniform-sized highly doped rods in the cladding is proposed. The uniform-sized highly doped rods play the same role as the segmented cladding and can provide effective coupling with high-order modes (HOMs). In the meanwhile, the fundamental mode (FM) can be well confined with a bending loss as low as 0.00073 dB/m at a tight radius of 10 cm. Numerical results indicate that the fiber can achieve a robust single-mode operation with a HOM to FM loss ratio as high as 52,431. Even though under a heat load of 55 W/m, the robust single-mode operation with an effective mode area higher than 1446 µm² can still be maintained at the bending radius of 10 cm.